OTFT – Challenges and opportunities

I recently took part in a panel session at CADTFT 2016 in Beijing, discussing the topic of ‘organic thin-film transistors (OTFT) – challenges and opportunities’.

The panel consisted of 12 experts from across the supply chain, covering materials, manufacturing process, device structures, modelling and layout, applications and markets, as well as fundamental research. This wide spectrum of expertise made for a fascinating and thought-provoking session. Here is a summary some of the highlights:

OTFT performance

OTFT is widely recognised as the most flexible TFT technology (the route to true flexibility for electronics), but has in the past had lower electrical performance – in terms of mobility. Today OTFT mobility routinely exceeds amorphous silicon (a:Si) levels, enabling high performance, colour, video rate displays. The panel discussed that there is perhaps an over-focus on mobility as the figure of merit for OTFT, and more emphasis should be put on stability of the TFT and the uniformity of these parameters over the substrate surface – both of which are important for manufacturability. Recent breakthroughs in stability and the understanding of fundamental mechanisms have led to a further increase in stability.

Manufacturing Processes

Today there are several OTFT process variants in development, with different process types likely to be relevant to different applications or performance requirements (as is true for inorganic electronics). For organic electronics, in the longer term we expect a convergence toward roll to roll (R2R) production methods, which will transform the cost structure of flexible electronics. In the short term, for display and sensor arrays using OTFTs, the focus is on getting the technology into existing manufacturing lines using current flat panel display (FPD) equipment – in order to get flexible displays into new product designs.

Applications

The market potential for flexible electronics is clear, and the route to truly flexible and stretchable electronics needs OTFT technology in order to be fulfilled. With a near-overwhelming list of applications (both existing and new markets), it is important to focus on the right areas. FlexEnable has already proven that OTFTs enable flexible components including colour, video-rate displays, fingerprint sensors, X-ray image sensors and integrated circuits. Applications in the short term include consumer electronics, automotive, digital signage, medical and security.

The need for flexible electronics is now clearer than ever, and organic electronics is the key to truly flexible displays and sensors with no compromise in performance compared to amorphous silicon. With supply chain partners and end-user companies combining efforts, the opportunities are vast and the future promising.